<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<meta name="viewport" content="width=device-width, initial-scale=1">
		<title>mywebsite</title>
		<style type="text/css">
			.box{
				/* padding-left: 20px;
				padding-right: 30px;
				padding-top: 40px;
				padding-bottom: 50px; */
				padding: 20px 30px 40px 50px;
				width: 500px;
				height: 300px;
				background: red;
			}
		</style>
	</head>
	<body>
		<div class="box">内边距</div>
	</body>
</html>